Mint, Burn and Cheque details should contain hash of
main net tx of Deposit and Withdraw invocation. They will
be formatted inside the contracts so alphabet nodes must
not modify them.
Signed-off-by: Alex Vanin <alexey@nspcc.ru>
On the `Deposit` events add gas balance check.
Make transfer only if the balance is greater
than the `GasTransferThreshold` that is defined
with environmental variable.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>